It is desirable to provide integrated circuit packages which facilitate the mounting of integrated circuit devices in high-density for a number of reasons. The speed of operation of VHSIC and VLSI devices is often significantly affected by the length of interconnecting leads between respective integrated circuit devices. For this reason it is advantageous to package plural devices in high-density to provide the shortest interconnection lead configuration feasible. It is also important to minimize interconnection lead lengths between connections of integrated circuit devices to minimize noise and cross-talk within a circuit. High-density packaging techniques also minimize noise and cross-talk.
Improved packaging densities also permit reduced system packages sizes and additionally reduced power supply requirements as a consequence of reduced lead and stray capacitances associated with interconnections between respective integrated circuit devices.
Typically, a single integrated circuit die is mounted within a dual-in-line circuit package, a leadless chip carrier or a leaded chip carrier and such packages are in turn interconnected to form a desired electrical circuit. The sizes of the respective packages are significantly larger than the sizes of the dies disposed within the packages thereby limiting the overall packaging density.
Various packaging techniques have been developed to improve integrated circuit packaging density. One package is disclosed in application Ser. No. 498,089 of the same assignee as the present invention. A high-density motherboard is therein described which has two major surfaces. Conductive pads are disposed on the major surfaces of the motherboard and oriented to electrically mate with input-output connections of specified integrated circuit devices. Input-output pins project from a pin edge of the motherboard and are typically provided in a dual-in-line arrangement to permit mounting of the package using typical dual-in-line mounting techniques.
Other packaging systems and structures are disclosed in U.S. Pat. Nos. 4,345,955; 4,338,621; 4,336,088; 4,332,778; 4,245,273; and 3,812,402.